Multiple bitrate encoding
For some time, both Windows Media and Real Media have had the option of merging different quality streams together which allows the clients player to intelligently work out what connection speed they are using and select the appropriate stream. For example, you could have one stream encoded at 37kbps for modem users, and another at 300kbps for broadband users.
Windows Media calls this Multiple Bitrate Streaming, Real’s equivalent is called Surestream.
The advantages are fairly obvious in that you only have to provide one link to your users for them to connect to your stream. The disadvantages that I have found is that it does not always work as well as it is supposed to.
Generally for modem users, the stream will play correctly at the low bit rate version. When connecting to a surestream or multibitrate stream through a broadband connection things normally work well until there is some network congestion at which point the stream fail over to the lower bitrate version of the stream, subsequently there are often problems in returning to the broadband stream which can take quite some time.
The other thing that I have noticed is that when using an older version of Windows Media Player (6.4) and connecting to a multi bitrate stream, it always seems to select the lower bitrate version even though I have plenty of available bandwidth.
Add comment August 5th, 2005